1. Field of the Invention
The present invention relates to a free wheeling adapter for permitting towing automotive vehicles without damage to the transmission and selectively to permit driving the vehicle.
2. Description of the Prior Art
Various selectively drive and/or free wheeling hub devices for use with automotive vehicles have been advanced. These devices are generally useful, but improvements in the mechanism for permitting driving the vehicle, and quickly releasing a hub for free wheeling still is a need. Further, the devices have to be easily attached to the existing wheel supports for the vehicle and cannot have excessive overhang on the axles, and thus must be compact in design, foolproof, and easily made for low cost.
Pat. No. 4,337,003, issued to Juhl on June 29, 1982 illustrates a selectively lockable or free wheeling device that is insertable between a vehicle wheel and its axle, and which includes a backing plate that mounts onto the wheel bolts of the vehicle. The backing plate carries a stub shaft or axle that is used for mounting a hub having a bolt circle identical to that of the wheel for the vehicle on which it is used so that the vehicle wheel can be mounted on the hub. The hub is normally free wheeling, but can be drivably coupled to the backing plate by the use of bolts that pass through the wheel bolt openings and the normally free wheeling hub to thread into the main support flange to effect a drive connection. This increases the difficulty of changing from a free wheeling system to a drive system when the vehicle is going to be driven, and increases the cost. Additionally, the provision of two separate wheel bolts is necessary, having different lengths, and if by accident one of the long bolts was used when free wheeling was desired, damage could result when the vehicle was towed or driven.
U.S. Pat. No. 4,266,646 to Telford illustrates a wheel hub that has a disengagable clutch or drive arrangement for free wheeling, and is designed to provide for a drive between a "live" vehicle axle and a hub. The drive is directly between the vehicle axle and the hub. It does use a spline arrangement for driving which can be engaged and disengaged. Springs are used to urge a drive nut into a lock or unlock position. However, it does not provide for a rapid connection to an existing automotive type wheel mounting which has a free wheeling hub in place on it.
U.S. Pat. No. 4,089,610 to Kleespies et al. illustrates a wheel hub that involves external clutching mechanisms. The device includes a sleeve with slots and a drive lug having ears extending radially. A spring forces the drive lug in the engaged position. While useful, the Kleespies device requires special adapters for the end of the vehicle driving hub and for connecting to the free wheeling hub.
Supplemental axles or emergency stub axles are shown in U.S. Pat. Nos. 1,410,863 to Woodson and 1,278,669 to Jacob. These show devices for mounting wheels on axles other than the primary axle provided on the vehicle, but do not show the free wheeling concept.
U.S. Pat. No. 3,251,630 to Astley shows a vehicle wheel assembly for a golf cart to permit towing such a golf cart without turning the differential or transmission by having a drive from the normally mounted wheel to the axle that can be released or disengaged.
The McReynolds device, U.S. Pat. No. 3,282,365, shows a golt cart having drive wheels that can be made freewheeling to facilitate towing of the cart. To disengage the driving wheel, a yoke must be removed from a freewheeling hub.
U.S. Pat. No. 1,904,371 to Hynan shows a demountable wheel lock that can be used for quick removal of the wheel, but does not show a free wheeling concept.
The Ponnequin device, U.S. Pat. No. 2,609,243, shows a splined sleeve used for engageing a splined axle on a freely rotating wheel. To allow freewheeling, a smooth collar is substituted for the sleeve. This device is not convenient for towing as disassembly is required.
U.S. Pat. No. 4,287,972 to Petrak shows an automatic clutch assembly whereby an annular, slotted cam gear causes a drive gear to move into locking engagement with a member to be driven automatically in response to application of torque to the drive gear. U.S. Pat. No. 4,327,821 to Telford shows an improved automatic locking clutch having a sliding clutch ring to minimize problems when a vehicle makes a transition from a two-wheel to a four-wheel drive mode.
Thus the art fails to show an easily used, readily made and conveniently attached hub that can be used for either drive or free wheeling operation such as that shown in the present device.